<title>车厢调度</title><link href="http://hzoi.com/tomorrow.css" rel="stylesheet"><div class="ui existing segment"><pre><code><span class="pl-cm">/*</span>
<span class="pl-cm">4</span>
<span class="pl-cm">1 4 3 2</span>
<span class="pl-cm">*/</span>
<span class="pl-cp">#include</span><span class="pl-cpf">&lt;cstdio&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span><span class="pl-cpf">&lt;stack&gt;</span><span class="pl-cp"></span>
<span class="pl-k">using</span> <span class="pl-k">namespace</span> <span class="pl-n">std</span><span class="pl-p">;</span>

<span class="pl-kt">int</span> <span class="pl-nf">main</span><span class="pl-p">(){</span>
	<span class="pl-n">freopen</span><span class="pl-p">(</span><span class="pl-s">&quot;carriage.in&quot;</span><span class="pl-p">,</span><span class="pl-s">&quot;r&quot;</span><span class="pl-p">,</span><span class="pl-n">stdin</span><span class="pl-p">);</span>
	<span class="pl-n">freopen</span><span class="pl-p">(</span><span class="pl-s">&quot;carriage.out&quot;</span><span class="pl-p">,</span><span class="pl-s">&quot;w&quot;</span><span class="pl-p">,</span><span class="pl-n">stdout</span><span class="pl-p">);</span>
	<span class="pl-kt">int</span> <span class="pl-n">n</span><span class="pl-p">,</span><span class="pl-n">c</span><span class="pl-p">,</span><span class="pl-n">ai</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span>
	<span class="pl-n">stack</span><span class="pl-o">&lt;</span><span class="pl-kt">int</span><span class="pl-o">&gt;</span> <span class="pl-n">stk</span><span class="pl-p">;</span>
	<span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span><span class="pl-o">&amp;</span><span class="pl-n">n</span><span class="pl-p">);</span>
	<span class="pl-k">for</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span><span class="pl-o">=</span><span class="pl-mi">1</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">&lt;=</span><span class="pl-n">n</span><span class="pl-p">;</span><span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">){</span>
	        <span class="pl-kt">int</span> <span class="pl-n">ans</span><span class="pl-o">=-</span><span class="pl-mi">1</span><span class="pl-p">;</span>
	        <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span><span class="pl-o">&amp;</span><span class="pl-n">c</span><span class="pl-p">);</span>
	        <span class="pl-c1">//printf(&quot;queue_front:%d stack_top:%d cu:%d\n&quot;,ai,stk.empty()?-1:stk.top(),c);</span>
	        <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-n">stk</span><span class="pl-p">.</span><span class="pl-n">empty</span><span class="pl-p">()</span> <span class="pl-o">||</span> <span class="pl-n">stk</span><span class="pl-p">.</span><span class="pl-n">top</span><span class="pl-p">()</span><span class="pl-o">!=</span><span class="pl-n">c</span><span class="pl-p">){</span>
                        <span class="pl-k">while</span><span class="pl-p">(</span><span class="pl-n">ai</span><span class="pl-o">!=</span><span class="pl-n">c</span> <span class="pl-o">&amp;&amp;</span> <span class="pl-n">ai</span><span class="pl-o">&lt;=</span><span class="pl-n">n</span><span class="pl-p">){</span>
                                <span class="pl-n">stk</span><span class="pl-p">.</span><span class="pl-n">push</span><span class="pl-p">(</span><span class="pl-n">ai</span><span class="pl-p">);</span>
                                <span class="pl-n">ai</span><span class="pl-o">++</span><span class="pl-p">;</span>
                                <span class="pl-c1">//printf(&quot;queue_front:%d stack_top:%d cu:%d\n&quot;,ai,stk.empty()?-1:stk.top(),c);</span>
                        <span class="pl-p">}</span>
	                <span class="pl-n">ans</span><span class="pl-o">=</span><span class="pl-n">ai</span><span class="pl-o">==</span><span class="pl-n">c</span><span class="pl-o">?</span><span class="pl-n">ai</span><span class="pl-o">++:-</span><span class="pl-mi">1</span><span class="pl-p">;</span>
	        <span class="pl-p">}</span>
	        <span class="pl-k">else</span> <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-o">!</span><span class="pl-n">stk</span><span class="pl-p">.</span><span class="pl-n">empty</span><span class="pl-p">()</span> <span class="pl-o">&amp;&amp;</span> <span class="pl-n">stk</span><span class="pl-p">.</span><span class="pl-n">top</span><span class="pl-p">()</span><span class="pl-o">==</span><span class="pl-n">c</span><span class="pl-p">){</span>
	                <span class="pl-n">ans</span><span class="pl-o">=</span><span class="pl-n">stk</span><span class="pl-p">.</span><span class="pl-n">top</span><span class="pl-p">();</span>
	                <span class="pl-n">stk</span><span class="pl-p">.</span><span class="pl-n">pop</span><span class="pl-p">();</span>
	                <span class="pl-c1">//printf(&quot;queue_front:%d stack_top:%d cu:%d\n&quot;,ai,stk.empty()?-1:stk.top(),c);</span>
	        <span class="pl-p">}</span>
	        <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-n">ans</span><span class="pl-o">!=</span><span class="pl-n">c</span><span class="pl-p">){</span>
	                <span class="pl-n">printf</span><span class="pl-p">(</span><span class="pl-s">&quot;NO</span><span class="pl-se">\n</span><span class="pl-s">&quot;</span><span class="pl-p">);</span>
	                <span class="pl-k">return</span> <span class="pl-mi">0</span><span class="pl-p">;</span>
	        <span class="pl-p">}</span>
	<span class="pl-p">}</span>
	<span class="pl-n">printf</span><span class="pl-p">(</span><span class="pl-s">&quot;YES</span><span class="pl-se">\n</span><span class="pl-s">&quot;</span><span class="pl-p">);</span>
	<span class="pl-k">return</span> <span class="pl-mi">0</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
</cpde></pre></div>